Field of the Invention
Aspects of the present invention generally relate to processing for transforming a path.
Description of the Related Art
Some glyph paths are used to form a font by filling a closed region that is defined by a path connecting a plurality of vertices (control points) in sequence. Bold processing for thickening the glyph path is discussed in Japanese Patent Application Laid-Open No. 8-101675. The bold processing for a glyph path discussed in Japanese Patent Application Laid-Open No. 8-101675 includes making the shape of a path one size larger by moving each control point in the direction normal to the advancing direction of the path, and filling a closed region that is defined by the path.
However, the bold processing discussed in Japanese Patent Application Laid-Open No. 8-101675 assumes that, in a case where there is a plurality of closed regions that constitutes a font, the advancing directions of the paths defining the respective closed regions are the same. Therefore, in a case where the advancing direction of the path is different with each closed region, the normal direction to move a control point may differ with each closed region, so that the area of a certain closed region may become small. In other words, a part of the glyph path may become thin.
For example, as illustrated in FIG. 8A, the advancing direction of a path defining an upper closed region of a glyph path for the katakana letter ni is clockwise (right-hand turning) and the advancing direction of a path defining a lower closed region of the glyph path is counterclockwise (left-hand turning). In this case, if the normal direction is set to the left-hand side relative to the advancing direction of a path, the upper closed region is transformed in such a way that the area thereof becomes large, but the lower closed region is transformed in such a way that the area thereof becomes small.